Ideal Gas Law Molecular Mass, the Mole, and Avogadro’s Number: Atomic mass unit: 1 u = 1.6605 × 10 -27 kg ⇒ the mass per mole (g/mol) of a substance has the same numerical value as the atomic or molecular mass of the substance (in u) n → # of moles N → # of particles N A → 6.022 × 10 23 mol -1 m → mass of sample m particle → mass of particle A N n N = m = m particle N Mass per mole = m particle N A Mass per mole m n = Ideal Gas Law: 8.31 J PV nRT R mol K = = i 23 1.38 10 J PV NkT k K − = = × Boyle’s law (applies if n and T are constant): i i f f PV PV = Charles’ law (applies if n and P are constant): f i i f V V T T =
